Cover assemblies have been utilized normally to conceal and protect the device mechanism and circuitry with which they are associated and to provide operator safety where a hazard might otherwise be present. In addition, functional considerations such as ventilation of the enclosed device must be accommodated. The cover hardware also affords the opportunity to enhance the esthetic appearance. Following such considerations it has been common to evaluate and make accommodation for the simplicity of mounting and securing the covers using appropriate hardware. Further it has been a design consideration to take into account the requirement for repositioning the cover structure for inspection and the total removal for any adjustments, repairs or replacements.
In the environment of a printer of the type commonly used with data processing equipment including a continuous forms tractor to render infrequent the loading of new paper supplies, there have been specific service problems that have not been reconciled with respect to the cover structure as regards the design and the mode of operation. It has been necessary in the past to remove the forms tractor as an incident of cover removal before any substantial part of the mechanism could be exposed for inspection, adjustment or repair. Although the paper tractor is nominally removable without great difficulty it still requires a substantial part of the service time since the normal procedure would be to remove the tractor, remove the covers, and reinstall the tractor for service purposes. When the servicing or repair is complete this process is reversed by removal of the tractor, reinstallation of the covers and thereafter reinstalling the tractor. In addition to the disabilities associated with the thus frequent disassembly and reinstallation of the tractor, the act of removing the tractor may impair the serviceability under some circumstances. Where the problem resides in the cooperation between the forms tractor and the associated paper handling portion of the printer, the disturbance of the total cooperating mechanism by tractor removal often renders difficult or impossible the identification of the problem. On other occasions the additional removal and reassembly of the tractor after service may reinstate an intermittent problem that was thought to be overcome or was undetectable in the disassembled state or as previously assembled during servicing.